Chlorinator Problem?

[Westcoastgills]

For the first time in 4 years we have an algae problem in our pool. We have an Intellichlor IC60 and its 2 years old. Its worked fine for the past two years, even in the hot weather in Nevada. We have not added any extra chlorine to our pool and never had a problem. But this year the chlorine is consistently low and adjusting the output of the chlorinator won't change it. All the lights are green on the unit and the salt level is 3350ppm. How can I tell if the unit is working properly?

Thanks

Dennis

 

[funandsun]

Hey Dennis,

Welcome to TFP, Do you have a good set of test results you can share or just pool store results?

 

[Westcoastgills]

Just from my local pool store. Are they not the best?

 

[kabutotx]

You definitely need your own test kit like the TF-100 or Taylor K2006C. Pool store's number can vary widely even next day.
A SWG is meant to keep chlorine levels normal for a clean pool. They are not meant to treat algae. They can't produce the chlorine fast enough. You will need liquid chlorine/bleach.
You need to do a Pool School - SLAM - Shock Level And Maintain To do that you need a FAS-DPD test like in the above test kits. We also need full test readings. The chlorine level needed is dependent on you CYA level.
Read: Pool School - ABCs of Pool Water Chemistry

 

[Westcoastgills]

Thank you. The odd part is we drained the pool this year to replace the water and the algae started right away, which leads me to believe the chlorinator is wonky as I know the pool was clean.

 

[Jezza]

It doesn't take much for algae to take hold if the required level of FC is not kept above the minimum level. A SWG can often be good at holding it at bay and what you usually notice is the large consumption of FC to the point where you question whether it is the SWG that's not producing chlorine.

 

[AimeeH]

Without a full set of reliable test results, it's hard to say. Since you drained, it could be that your CYA is too low or non existent? To help hold chlorine.

 

[funandsun]

Hey westcoastgills, not to keep beating that dead horse but yes, please give real thoughtful consideration to taking over your own testing. It really is the only 100% absolute way that you can realistically ever expect to maintain your pool properly and to your high expectations (meaning, Clean and Clear).

Welcome to TFP, everyone here is chomping at the bit to help you learn about and get your pool straightened out.

 

[Dirk]

How many hours per day have you been running your IC60, and at what percentage?

While others here are troubleshooting what your chemistry is doing, we can determine where your SWG is in terms of "life." They have a finite number of hours of use, and then they're done. Your IC is well oversized for your pool, so two years if not all that long, but we can check and make sure with some quick math. Or here's another way to rule out end-of-life:

From the most current IC owner manual:

IntelliChlor SCG Usage Hours Meter

The IntelliChlor® SCG provides a built-in cell “usage hours” meter that reports how many hours IntelliChlor hasbeen operating. The IntelliChlor SCG is designed to operate for approximately 10,000 hours before replacement is needed or roughly five (5) years of average use.

To access the system status mode:

1. Press and hold the MORE button for three (3) seconds until the lights scroll across the unit.

2. One (1) of the five (5) Sanitizer Output LED indicators (20%, 40%, 60%, 80% and 100%) will be lit,indicating the hours of usage.

The Output LEDs are as follows:

• 2000 hours (20% LED on)
• 4000 hours (40% LED on)
• 6000 hours (60% LED on)
• 8000 hours (80% LED on)
• 10,000 hours (100% LED on)

 

[JamesW]

Check for scale and clean only if necessary.

What percentage is the cell production set to and what is the run time?

A full set of results is critical to assessing the situation.

Do an OCLT (Overnight Chlorine Loss Test) to see what that shows.

If the cell is clean and not showing an error, it's probably working.

 

[Westcoastgills]

I did have a test kit I bought last year and I just went and got fresh testing agents. So I will be testing myself from now on.

1. The pool was drained about 2 months and cleaned. New water and salt was added.
2. Last year the pool ran about 8 hours a day @ 35% on the SWG.
3. It started the same this year, but then the algae started and I bumped it up to around 60%.
4. I have been adding the shock packets weekly (73%) based on what the pool store tells me. But the chlorine stay low to non-existent.

I have reviewed the link posted above about the SLAM process and have started that.

Thanks for all the feedback. Figures the year I drop my pool guy because it appeared he never did anything my pool burps on me!!!

Dennis

 

[Dirk]

Well, even if you ran your SWG everyday, for 8 hours, at 60% you've only used 1752 hours per year, so that rules that out (at two years, that's well under your IC's 10000 hr expected life). It doesn't rule out that the cell might be defective in some way, and has reached it's end-of-life for some other reason, but we don't need to go there until you rule out the other chemical possibilities, including build up on your cell's internal plates.

BTW, a pool store, and/or a pool guy can help you achieve what looks to be a healthy pool (clear water), but that doesn't mean it's actually sanitized. They can help you achieve that, too, but it is usually at the expense of adding chemicals that will eventually backfire, or necessitate a water exchange, or even damage your plaster.

It might seem like you were better off with a pool guy, but it likely only seems that way. If you continue to explore this site, and the TFP way of managing your pool water, and embrace its methods, you'll save money, your water will be cleaner and healthier, and your pool will last longer. That might seem to good to be true, but it only seems that way!

The experts here will have your dilemma sorted out for you in short order. Trust their advice...

 

[kabutotx]

An IC60 running at 35% for your pool only produces 1.5FC in 8 hours. You probably need to be running 80% depending on your burn off.
To test your SWG, take a FC reading at sundown. Run your SWG and take a test at sunrise and see what your FC is then. You will need a FAS-DPD chlorine test (from the TF-100 or Taylor K2006) to get this exact. Strips and regular OTO chlorine tests aren't exact enough.
To test burnoff, do the opposite. Test at sunrise and again at sunset to get FC used by the sun.
This all assume you have no algae in the pool.
Really need to know your CYA level.

 

[funandsun]

I did have a test kit I bought last year and I just went and got fresh testing agents. So I will be testing myself from now on.

We have another TESTER!!! Yes!

Ouch on the shock packets weekly. Get a full battery of tests, lets see where that CYA is.

 

[Westcoastgills]

Update:

With my own noobish testing I discovered:

1. pH was high-8.2, which was brought down to 7.4.
2. Last 2 tests at the pool store showed the CYA @ 60. When i did the test it showed 0. I went to the pool store to get new reagent as I thought maybe it was old and not reading properly. While there I had a sample tested again. Pool store employee says "No wonder you have a problem, your CYA shows 0". I laughed and gave him a hard time and showed him the last 2 test results (one from 3 days ago) that showed 60. To be fair he is the weekend guy and didn't perform the previous 2 tests. So I got it back up to 70.
3. Added chlorine according to the tables listed elsewhere on this website to raise to appropriate levels.

Will monitor.

Thanks for all the input and help. I really appreciate it.

Dennis